Guardrails are commonly seen along the shoulder of selected sections of roadways. The guardrails comprise a strip of material, typically twelve (12) gauge galvanized steel, anchored to posts spaced apart from one another. A guard rail mounting block is disposed between the guard rail and each post. The guard rail strip may be fabricated from other materials such as aluminum, steel, fiberglass, or even synthetic materials. Most segments of guardrail are approximately twelve (12) feet in length and about ninety (90) pounds in weight.
This application is closely related to the following: U.S. patent application Ser. No. 10/885,398 filed on Jul. 6, 2004; and U.S. patent application Ser. No. 10/385,006 filed on Mar. 10, 2003; which claim priority from U.S. Pat. No. 6,530,560 which issued on Mar. 11, 2003 from U.S. patent application Ser. No. 10/079,280 filed on Feb. 19, 2002 and U.S. Pat. No. 6,758,627 which issued on Jul. 6, 2004 from U.S. application Ser. No. 10/001,903 filed on Nov. 15, 2001 which claims priority from U.S. Provisional Application Ser. No. 60/249,037 filed on Nov. 15, 2000 the substance of all of which is incorporated herein by reference thereto.
The strip of material conventionally is undulating in cross section to absorb energy when impacted by a vehicle. Such energy absorption is desired in an effort to prevent the vehicle from leaving the roadway or at least to influence the direction of the vehicle prior to it leaving the roadway. The corrugated strip may be about nine (9) inches wide with two crowns simulating the letter “W”.
The posts typically are a selected length of a wide flange I-beam and are driven into or otherwise suitably anchored in the ground. Preferably, the support posts do not break off at ground level. It is preferred to have the posts yield upon impact in an effort to assist the guardrail in dissipating the impact force received from a vehicle.
While the strips of guard rail could be fastened directly to the posts it is preferred to have a spacer block disposed between the guardrail and the support post and thereby spacing the guardrail from the support posts. The spacing helps keep the wheels of the automobile from coming into contact with the support posts and thereby perhaps guiding the vehicle and providing at least some response time for the driver to regain control of the vehicle.
Conventional spacer blocks are typically made of wood but they have many shortcomings such as deteriorating with time, they are excessively heavy, they can give installers splinters and the typically contract and expand with seasonal changes. In addition when made from treated wood the chemicals which may be toxic leach out into the environment. While there are some plastic spacer block substitutes on the market, they are generally deficient in that they are typically wood block designs formed from a plastics material.
In most installation instances, it requires two to three people to attach a twelve (12) foot section of guard railing to support posts when using conventional spacer blocks. Typically one person is needed to hold the guardrail while another person aligns and holds the spacer block in position. A third person is often required to insert bolts used to secure the railing to the posts.